Jolt ramming-machine.



W. CASPARY.

Patented M11120, 1915.

2 SHEETS-SHEET 1.

I'HE NOVIS PEYERS (30., PHOTO-LITHPH WASHINGTOPLILL C4 W. CASPARY.

JOLT RAMMING MACHINE.

APPLICATION FILED JAN.27. 1914.

Patented Apr. 20, 1915.

Z SHEETS-SHEET 2.

WITNESSES INVENTOR HE NORRIS PETERS 60., PHOTO-LITHQ. WASHINGTON. D. Cv

WILLY CASPAEY, OF DURLACH, GERMANY.

JOLT RAMMING-MACHINE.

Specification of Letters Patent.

Patented Apr. 20, 1915.

Application filed January 27, 1914. Serial No. 814,801.

To all whom it may concern:

Be it known that I, WILLY CAsPARY, a subject of the King of Prussia,residing at Durlach, Baden, in the Empire of Germany, prays that LettersPatent may be granted to him for the new and useful Improvements in JoltRamming-Machines, of which the following is a specification.

This invention relates to jolt ramming machines and it has for one ofits primary objects the provision of a novel arrangement of jolt rammingmachine and operating means therefor which is economical and effectivein operation and which has the advantages of the fluid pressure actuatedand positively actuated types of jolt ramming machines but which hasnone of the disadvantages of such types. Another object of the inventionresides in the provision of a novel form of operating means whichpermits of regulation of the intensity of the impact or jolt of themachine, and one in which vibration of the machine and also of thesupporting structure therefor is reduced to a minimum. More specificallystated my invention contemplates an improved pneumatically actuated joltramming machine.

The foregoing, together with such other objects as may hereinafterappear, or are incident to my invention I attain by means of aconstruction, the preferred embodiments of which I have illustrated inthe accompanying drawings, wherein- Fig. 1 is a vertical section throughone form of olting machine which embodies my invention; Fig. 2 is avertical section of another form of my invention; Fig. 3 is a sectiontaken on the line III-III of the device shown in Fig. 2; Fig. 4: is anenlarged sectional showing of a detail of the form of apparatus shown inFigs. 2 and 3; Fig. 5 is a section taken on the line V of Fig. 4; andFig. 6 is a section taken on the line VI of Fig. 3 but drawn on a largerscale.

Jolt ramming machines of the fluid actuated type usually comprise acylinder in which is mounted a reciprocating piston or plunger whichcarries a mold table and a which is adapted to impact on the cylinder onits downward stroke. This type of machme 1s actuated by the introductionof fluid pressure into the cylinder beneath the plunger and requires, inaddition to an independent air compressor or other independent source ofpressure supply, considerable pipmg from which there is a continuousloss of pressure through leakage, all of which renders machines of thistype expensive. In jolt ramming machines of the mechanically actuatedtype, that is, machines which are positively operated through mechanicalmeans, there is rapid wear because of the vibrations and other stressesnecessarily incident to this type of apparatus. This re sults indecreased efl iciency and shortens the life of the machines. Myinvention is designed to overcome these difficulties and to this end Iprovide the following mechanism.

Referring now to Fig. 1 of the drawings, it will be seen that theapparatus comprises a main casting 7 the upper portion of which isformed into a cylinder 8, open at the top. Mounted in the cylinder 8 isa piston 9 which is reciprocated by means of a crank shaft 10 throughthe medium of the usual connecting rod 11. The crank shaft 10 is mountedin the frame 7 beneath the cylinder 8 and carries at one end a fly wheel12, which also serves as a means for imparting rotary movement to theshaft, a belt drive from any suitable source of power being preferablyemployed. Intermediate its ends the cylindrical portion 8 of the frame 7is provided with an annular flange 13 which serves as an impact anvil,and the exterior of the cylindrical portion above such flange turneddown to fit the interior of a cylinder 14 depending from the lower faceof the mold table 15. When the table 15 is in normal position, that is,lower position, the lower edges of the cylinder 14 rest upon the impactanvil 13, the length of the cylinder 1% being such that a clearancespace 16 is provided between the lower face of the table 15, the top ofthe cylinder 8, and the upper face of the piston 9 when the latter is inupper position. The chamber 17 of the casing or frame 7 beneath thecylinder 8 and through which shaft 10 extends, is preferably made airtight. A by-pass 18 is provided in the wall of the cylinder 8 andextends from the top thereof to the bottom where it opens into thechamber 17; mounted in the bypass is a check valve 19 which is normallyheld on its seat by means of a spring 20, the valve being arranged topermit a flow of air to the space above the piston but preventing flowfrom such space into the chamber 17; and a screw 21 is provided wherebyto unseat the valve 19 for purposes of regulation as will furtherappear.

The operation of the apparatus is as follows: On the up stroke thepiston 9 compresses the air in the space between the table and the topof the piston since the air is confined therein by the valve 19, and thetable 15 is lifted on a cushion of compressed air.

' After the piston reaches the upper extreme of its travel, the upwardmovement of the table continues by virtue of the expansion of theconfined compressed air and by its own momentum. By the time the tablehas come to rest, the piston has partially completed its downwardmovement and the table falls by the action of gravity and impactsagainst the flange or anvil 13, thereby effecting the ramming of themold or molds carried on the table. This operation is repeated withevery reciprocation of the piston.

The advantage obtained by the provision of the by-pass and check valveis that the formation of a vacuum or a so-called partial vacuum, in thespace above the piston is prevented. That there is a tendency to form avacuum will be clear from the fact that during a certain period of themovement of the table and the piston, the two are separating. Duringthis period air is drawn from the chamber 17 through the by-pass intothe space above the piston. The presence of a vacuum or a partialvacuum, so-called, in the space above the piston would result inaccelerating the downward movement of the table and in increasing theforce of the impactto an undesirable degree. By providing a flow betweenopposite ends of the piston, the mold table falls by action of gravityalone. It will be obvious that the valvular arrangement also affords ameans for regulating the force of the impact, this being accomplished byadjusting the screw 21 so as to slightly unseat the valve 19, therebyper mitting a small leakage from the space above the piston into thechamber 17, as a result of which the upward movement of the table willbe restricted with a consequent reduction in the force of the impactwhen the table falls. That this is the case, will be clear from the factthat the cushion of air will-not act as effectively when there isleakage, and will therefore not raise the table as high. It will also beapparent that in cases where a number of machines are operated from onesource, any one ofthe machines can be temporarlly cut out by completelyunseating the valve 19 and permitting a free, unobstructed flow betweenopposite ends of the piston, in which case the table will not be movedby the piston.

It will be apparent that the operation of the apparatus is economicaland effective, and that beside the advantages incident to the ability toregulate the force of the impact, the construction is such as toeliminate to a large extent excessive vibration of the machine and thefoundry floor.

In the type of machine described, the jolt is obtained by the falling ordropping of the table onto an anvil or impact member. In theconstruction shown in Figures 2 and 3, the jolt is imparted by a blowdelivered in an upward direction, the general construction, however,being substantially the same. As in the construction previouslydescribed, the framework 7 is provided at its upper portion with acylinder 8, but the cylinder 14: on the table 15, however, works withinthe cylinder 8 instead of on the outside thereof, and working within thecylinder 14: is a hollow piston which in this construction constitutes amovable impact member 22. The piston 9 reciprocates within the impactmember and operates through a cushion of air to elevate the impactmember in the same manner as the table is elevated in the constructionof Figure 1. A small space 16 is provided between the lower face of theimpact member and the upper face of the piston 9, and a by-pass 18 opensat the top into such space and at the bottom into the chamber 17 saidby-pass being controlled as before by means of valve mechanism, whichvill be further described.

The operation of this embodiment of the invention is as follows. On theupward stroke of the piston 9, the air confined in the space above thepiston is compressed and the impact member 22 is moved upwardly alongwith the piston, the movement of the impact member continuing after thepiston has reached the upper extreme of its movement and has traveleddownward a portion of its return stroke. In rising, the impact member 22impacts against the table 15 and effects the ramming of the mold. Theimpact member comes to rest and falls by the action of gravity in themanner previously described. In the meantime, the table 15 has movedupwardly a slight distance and then falls, the downward movement of thetable 15 being cushioned on the air confined between the end of thecylinder 14 and the bottom of the cylinder 8. The table thus returns toinitial position without a jolt. While the impact member 22 is falling,the piston 9' has completed its downward stroke and is again movedupwardly and the downward movement of the impact member is arrested bythe cushion of air above the piston. As the upward movement of thepiston continues, the impact member is again projected upward in themanner described, This form of apparatus is particularly, adapted foruse in connection with large machines in the operation of which it isundesirable to have the impact taken directly upon a portion of theapparatus. It will be apparent that in this construction, the impact isdelivered by the upward blow of what may be termed a floating impactmember which in itself imparts no jolting to the apparatus because ofits support on the cushion of air above the piston. The advantages ofthis construction will be apparent. It will be noted that a number ofleakage ports 23 are provided in the walls of the cylinder 14 closelyadjacent the lower face of the table 15, the object being to permit a.free circulation above the impact member, thereby preventing theformation of a vacuum above the impact member on the downward stroke ofsuch member, and also preventing the confinement of air above the impactmember which would take away from the sharpness of the blow delivered tothe table by the impact member.

Attention is now directed to Figs. 4;, 5, and 6 which are enlargedsectional views of they by-pass 18 and valve mechanism pro-- vided inthis type of apparatus. The valve 19 in this construction is alsopreferably of the check valve type and is a circular plate, the edges ofwhich are engaged and guided by several ribs 19 projecting into thevalve chamber (see particularly Fig. The valve permits a flow from thelower chamber to the chamber 16 and adjustment is afforded by the screw21 by means of which the valve may be opened to any desired degree. Thespring 24: is provided in order to insure the seating of the valve whenthe screw 21 is retracted. By a slight opening of the valve, the forceof the impact or jolt may be regulated by the change in the throw of theimpact member 22, and by moving the valve to wide-openposition, themovei'nent of the impact member is stopped as before.

[an advantage common to both types of apparatus resides in the fact thatheat losses due to compression. and expansion are to a large extentavoided. The compression and expansion of air takes place in the samespace and a considerable portion of the heat that is formed oncompression is taken up when expansion talres place, which eliminatesthe necessity of water cooling and reduces power losses.

What I claim is:

1. A jolt ramming molding machine comprising in combination with amovable j olting member, a reciprocatory piston, the move able memberand piston being arrangedto arovide a cushion of air therebetween, andmeans for reciprocating the piston whereby to impart movement tothe-movable member through the cushion of air.

2. A olt ramming molding machine comprisingin combination with a movablejolting member mounted for free vertical movement, a reciprocatorypiston working within said member but spaced apart therefrom to providea chamber for confining a cushion of air, and means for reciprocatingthe piston; whereby to impart upward movement to the said member throughthe medium of the cushion of air.

3. A jolt ramming molding machine comprising in combination with amovable jolting member mounted for free vertical movement, areciprocatory piston for actuating the jolting member, there being aspace between the piston and said member for con fining a cushion ofair, means for reciproeating the piston whereby to impart upwardmovement to the jolting member through the medium of the cushion of air,and means for preventing the formation of a vacuum in said space on thedownward stroke of the piston. r

4. A jolt ramming molding machine comprising in combination with amovable jolting member mounted for vertical movement, a reciprocatorypiston for operating said member, an air chamber above Said piston andbetween the piston and movable member and an air chamber below saidpiston, a bypass from the upper to the lower chamber, a valvular devicecontrolling said by-pass, and means for reciprocating the piston, saidpiston imparting movement to the movable member through the medium ofthe air in said upper chamber. I

A jolt ramming molding machine comprising in combination with a movablejol ing member, a reciprocatory member for actuating said joltingmember, and an in tel-posed yielding movement-trausmittingmeans throughthe medium of which the reciprocatory member imparts movement to thejolting member.

6. A jolt ramming molding machine comprising in combination asubstantially vertical cylinder, a mold table having a dependingcylindrical portion slidably guided on the exterior of the cylinder forfree vertical movement, and a piston reciprocating within the cylinderfor operating the table, there being a. space between the piston and thetable to provide a cushion of air therebetween.

7. A jolt ramming machine comprising in combination a movable moldsupport, a movable actuating 'member adapted to impart movement to thesupport, and an interposed yielding movement-transmitting means throughthe medium of which the said member imparts movement to the support.

8. A jolt ramming machine comprising in eembinatio'n a movable moldsupport, and signed my name in the presence of the two .a movableactuating member thereforgthere subscribed Witnesses.

being a'cushion of air interposedbetween r i V r said member and said"support whereby ILL} CASPARX' 5 movement is transmitted to the latterWhen Vitnesses:

said member is moved. S. S. BERGER, In testimony whereof I have hereuntoS. HEPTIAM.

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7 Washington, D. C.

